Terminal for pneumatic-despatch-tube apparatus.



No. 873,565. IPAKTENTED DEC. 10, 1907'.

- 1. w. LITGHFIELD. TERMINAL FOR PNEUMATIC DESPATGH TUBE APPARATUS.

APPLICATION FILED DEC. 9, 1905.

2 SHEETS-SHEET 1.

No. 873.565. PATENTED DEC. 10, 1907.

I. W. LITGHFIELD. TERMINAL FOR PNEUMATIC DESPATUH TUBE APPARATUS.

APPLICATION FILED 1920.9.1905.

2 SHEETS-SHEET 2.

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UNITED STATES PATENT OFFICE.

ISAAO W. LITGHFIELD, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO LAMSON CONSOLIDATED STORE SERVICE COMPANY, OF NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented Dec. 10, 1907.

Application filed December 9. 1905. Serial No. 291.043.

To all whom it may concern:

Be it known that I, ISAAC WV. LITGHFIELD, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Terminals for Pneumatic -Despatch-Tube Apparatus, of which the following is a specification.

My invention relates to improvements in pneumatic despatch tube apparatus and particularly to receiving terminals for systems in which the transmitting force is atmospheric pressure.

The object of this invention is to produce a terminal which will deliver the carrier re liably against any amount of atmospheric pressure usually encountered in such sys tems. In terminals heretofore used for this purpose when the lines are extremely long and the atmospheric pressure is very great (particularly in the terminals located near the source of power) the carriers would not be delivered, and to overcome this difficulty, expensive apparatus equipped with double and balanced valves have to be utilized. 1

In my terminal a satisfactory delivery is insured by providing a relief chamber located at the mouth of the delivery tube which prevents a sudden influx of atmospheric pressure from acting directly on the carrier in opposition'to its course of transit, when the valve is opened by the impact of the carrier. This chamber being continually in communication with the source of power causes the air to take a shorter course upon the opening of the valve and enter the chamber surrounding the delivery tube, thence being drawn into the suction pipe connected with the blower. This action permits the carrier to pass through the delivery valve without being excessively retarded by the sudden influx of air.

In the accompanying drawings which illustrate a construction embodying my invention, Figure 1 is a side elevation of the terminal. Fig. 2 is a front elevation of the same. Fig. 3 is a vertical longitudinal section. Fig. 4 is a sectional View on the line X X Fig. 3 looking in the direction of the arconnected with the source of power. Below the delivery tube A and extending forward from the center of said delivery tube is a chamber O which is separated from the chamber P formed by the casing B by means of a diaphragm D, said diaphragm being perforated with holes E. These holes are slightly smaller than a ten cent piece, thereby preventing the possibility of any loose change working into the vacuum tube. The delivery tube A is perforated with holes F which are interposed around said tube and connect said tube with the source of air supply. Controlling the opening formed by the relief' chamber O is the valve G which is hinged at 11. This valve is set at an angle to the delivery tube A and is of sufficient rigidity to prevent collapsing into that part 0 of the relief chamber O connecting with the chamber P. Attached to the face of the casing B formin the relief chamber O is the receiving chute E into which the carriers are ejected. A carrier entering the delivery tube A in the direction indicated by the arrow, arrives opposite the perforations F which serve to balance the carrier within the tube preventing it from being pulled against the air pipe side of the delivery tube. The carrier now strikes the valve G at an angle and causes the force of impact to be localized at one point providing an initial opening thereby for admission of air. The portion O of the relief chamber O extending near the fulcrum H of the valve G causes the air rushing through the initial opening to quickly equalize the pressure upon the valve allowing it to open fully for the passage of said carrier; in the meantime, the inrush of air into the relief chamber is partially prevented from acting directly against the carrier by taking a course through the said chamber O, through openings E and thence into the upper chamber P surrounding the delivery tube A and connecting with the source of power. This action causes the carrier to discharge easily and quietly into the chute L.

Having thus described the nature of my invention and set forth a construction embodying the same, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a terminal for pneumatic despatch tube apparatus, a transmission tube, a valve norma y closing the delivery opening of said terminal against atmospheric pressure, and a chamber located between the mouth of said transmission tube and said valve for relieving the vacuum in front of said carrier upon the impact of the carrier upon said valve and for diverting and preventing the inrush of air from acting upon and retarding the delivery of the carrier.

2. In a terminal for pneumatic despatch tube apparatus, a chamber surrounding the transmission tube and connected with the source of power, perforations connecting said chamber with the transmission tube and located in said tube opposite the connection to the source of power, a relief chamber located at the mouth of said transmission tube and connected with the chamber surrounding the transmission tube, a valve normally closing the lower part of said relief chamber and adapted to open outwardly, said relief chamber operative upon contact of the carrier with said valve for relieving the atmos pheric pressure exerted against said carrier upon the opening of said valve.

' 3. In a terminal for pneumatic despatch tube apparatus, a chamber surrounding the transmission tube and connected with the source of power, perforations connecting said chamber with. the transmission tube and located in said tube opposite the connection to the source of power, a relief chamber located at the mouth of said transmission tube, a diaphragm with perforations therein connecting said relief chamber with the chamber surrounding the transmission tube, a valve normally closing the lower part of said relief chamber and adapted to open outwardly,

said relief chamber operative upon contact of the carrier with said valve for relieving the atmospheric pressure exerted against said carrier upon the opening of said valve.

4. In a terminal for pneumatic des atch tube apparatus, the combination of a 0 amber surrounding the transmission tube and connected with the source of power, perforations connecting said chamber with the transmission tube and located in said tube opposite the connection to the source of power, a relief chamber located at the mouth of said transmission tube and connected with the chamber surrounding the transmission tube, and a valve normally closing the lower part of said relief chamber and mounted at angles with said transmission tube.

5. In a terminal for pneumatic despatch tube apparatus, a transmission tube, a relief ISAAC W. LITCHFIELD.

Witnesses:

C. L. RODGERS, HOWARD O. TURNER 

